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33646

General Discussion Area / Re: LPG installation WIP

« on: 30 November 2007, 19:49:11 »

Does it now run OK on petrol without fault codes appearing?

At idle, on petrol, fully warmed up, what does the LPG ECU say? RPM being reported correctly? Lambda sensor signals both cycling between around 0.2 and 0.8 volts? Injector durations roughly the same and, at a guess about 3ms for each cylinder? Battery voltage plausible? Manifold pressure around 0.3 bar? Temperatures (vapouriser and LPG) reading OK?

Just remembered we had to change the injector configuration to 1 ohm injectors on James' install. Have a look on the side of the coil of your gas injectors and see if they are 1 ohm jobs. System defaulted to 3 ohm.

We had a strange issue with the controller software during one of our calibration attemps. It appeared to lock up and left the engine running with an odd combination of a couple of cylinders on petrol and a couple on lpg. Restarted the software, restarted the car and tried again and it was fine.

Might be worth switching to LPG and setting all the cylinders back to petrol using the little switch icons on the lower right hand side of the screen. Then switch one pot at a time to LPG and see if any or all cause running issues.

.. and I'll send that configuration file to you in a minute

Kevin

33647

General Discussion Area / Re: LPG installation WIP

« on: 30 November 2007, 14:17:01 »

Problem with Romano kit is when injectors are full open it drops to petrol rather than remains full open.
 
AGWW recommended shortening the duration - mine is about same as petrol duration but I am sure it is a bit weak.
 
If I up the pressure I could lock the injectors as they lock at just under 3 bar.

Going lean at full revs and full throttle is not a good place to be. I'd be a bit wary of taking fuel out. Certainly monitor the Lambdas and make sure they stay pegged firmly on rich throughout the whole rev range at full throttle.

The problem with running out of injector flow is that, even if it didn't go lean when you were tuning it, if additional fuel is required for some reason (say intake temperature is lower, gas pressure drops, baro pressure is higher, etc) there's nothing else to give and it will go lean.

What gas pressure do you currently run? James' is 1 bar. I guess tweaking it up a little is an option, as long as there are no signs of problems with running out of reolution at the low end. Lambda signals were bobbing up and down nicely at idle?

Kevin

33648

General Discussion Area / Re: LPG installation WIP

« on: 30 November 2007, 13:52:45 »

Regarding the fuelling, the auto calibration claimed James' nozzles were too big at 2.5mm but we ignored this. Injector duration was slightly shorter than for petrol at idle but we found it needs a lot more fuel in the map at higher durations when manually mapped, so this is no bad thing. It was just popping up an "injectors full open" warning when revved to 6k, but the fuel mix was staying rich so not a real issue.

Kevin

33649

General Discussion Area / Re: LPG installation WIP

« on: 30 November 2007, 09:16:06 »

Oh, and I'll send you that file with James' settings tonight. I can't look at them without the ECU connected, or so it would seem, but I can send you the file. In fact, given that yours is also a 2.5 on 2.5mm gas nozzles, the fuelling should be set up pretty darn close.

Kevin

33650

General Discussion Area / Re: LPG installation WIP

« on: 30 November 2007, 09:14:22 »

Glad there appears to be light at the end of the tunnel.  Real bad luck that they decide to die at the same time

I'm guessing their cables had got a bit fragile with the heat and got disturbed during the install?

I don't remember the Lambda wires (we're talking about the ones on the LPG loom?) being different gauge but the colours ring a bell. One probably got made up with the wrong gauge cable :-/

I found if you take off the cover from the ECU connector you can run the wires down through the engine loom, into the connector and you can just solder them to the very top of the pins on the ECU connector.

Kevin

33651

General Discussion Area / Re: LPG installation WIP

« on: 23 November 2007, 20:57:58 »

KM=kilowatts, Jeremy confirmed that it was 2.5mm i had worked it out to be 2.3mm 170bhp divded by 4 = 42.5 per cylinder, 1KW is about 3/4 of a BHP = 31kw.
 

Or even 6?

 

Kevin

33652

General Discussion Area / Re: LPG installation WIP

« on: 23 November 2007, 00:07:06 »

I installed the Stag-300 software and had a play with it this evening.

I discovered that :

a) The instruction manual is a bit sparse and it's not immediately apparent what's going on.
b) If you go the the settings page there are configuration options for both the temperature and pressure sensors with a good number of options for each.

I'm wondering if the temperature sensor is selected wrongly and this is why the vapouriser temperature is reading incorrectly and, possibly, the pressure sensor could also be wrong explaining why the pressure reading drops so drastically on gas.

Combined with the small nozzle diameter this might explain what's wrong.

There is a table of nozzle diameter against engine power per cylinder however the power iunits are "KM". I wonder if this means kilowatts or BHP :-/

If BHP, then 2.5mm seems to tally with the output of a 2.5 V6 however they really need to match the petrol injector flow rate rather than engine output, I suspect (to give as close as possible a 1:1 mapping of injector durations).

Let's see what the weekend brings.

Kevin

33653

General Discussion Area / Re: LPG installation WIP

« on: 22 November 2007, 19:35:06 »

Yes, I've been reading the manual. No way to manually change the sensor settings?

I'd be intrigued to know how the auto calibration sets the map for the higher pulse widths as that would require the engine to be under load (and it would be open-loop, so no way to tell if it's rich or lean). I assume it's an educated guess.

Anyway, first things first. Out with the 2.5mm drill bit.

Kevin

33654

General Discussion Area / Re: LPG installation WIP

« on: 22 November 2007, 09:47:03 »

Is the vapouriser temperature sensor integrated into the unit or a screw-in device like a gauge sensor?

Just thinking we can maybe compare resistance readings with JV6CDX's one?

We can also substitute resistances to force it to read a sensible value, which might get you up and running. You'd have to change over to gas manually or else it would try to do it on a stone cold engine but otherwise it might help.

Kevin

33655

General Discussion Area / Re: LPG installation WIP

« on: 21 November 2007, 09:26:31 »

Would running lean kill a lambda? As far as I know, it's only a sensor, to sense the gasses...?

but if we have leaned it off too much and it has heated up badly then i was under the impression it could be damaged

I very much doubt running lean could have killed the Lambda sensor. I still suspect a wiring issue.

Unless it was driven hard with a lean mixture (not something to do until you're sure the engine is tuned perfectly), in which case the Lambda sensor could have been subjected to too high a temperature, I'm sure the problem lies elsewhere.

Kevin

33656

General Discussion Area / Re: LPG installation WIP

« on: 20 November 2007, 22:23:10 »

Could always pop in and see JamesV6CDX and myself on the way back as we'll be tackling his install this weekend. It's on the way from Epsom to Plymouth (pretty much). A few more heads under the bonnet may spot something...

Kevin

33657

General Discussion Area / Re: LPG installation WIP

« on: 19 November 2007, 17:13:20 »

i reckon we have killed a Lambda

Make sure you've got the LPG ECU configured for narrow band (voltage) lambda inputs not wideband.

The knock sensor could have been invoked when it was running lean

It's unlikely unless you were driving it under load I'd say. The error code hints more at an "I'm getting no signal from the knock sensor" rather than "your engine is knocking" but they don't always mean what you'd expect. Can anyone expand on these codes?

Kevin

33658

General Discussion Area / Re: LPG installation WIP

« on: 19 November 2007, 13:58:02 »

A quick google revealed this: No idea how accurate :-/

12 Initiation of diagnosis

37 Fault code light low voltage

38 Oxygen sensor voltage low

98 Oxygen sensor wiring break / open circuit

17 Knock sensor 2 No change in voltage


Looks like one of the O2 sensors and one of the knock sensors are not happy. I guess this could have invoked a "safe" ignition timing hence the poor economy.

Kevin

33659

General Discussion Area / Re: LPG installation WIP

« on: 19 November 2007, 13:51:35 »

I don't know what those codes refer to but what immediately springs to mind is that maybe the connections to the Lambda sensors are disturbing their operation on petrol and it's running rich. Maybe worth removing them for now?

Otherwise, could be that it got the hump about something when it was running badly on LPG and the faults are not actually present on petrol.

Kevin

33660

General Discussion Area / Re: LPG installation WIP

« on: 18 November 2007, 17:23:24 »

Don't suppose the LPG and vapouriser temperature sensors are wired wrongly (swapped over?)

Don't even know if this is possible - are they both on or near the vapouriser?

The poor running could then just be down to it not having calibrated.

Kevin